The cooling or the operation of the cooling section has a decisive effect on the quality and the properties of the sheet metal produced. The cooling section of a heavy plate train is used especially to set the material properties of the sheet metal in the desired way.
During cooling of heavy plate, because of the comparatively large thickness and the heat content associated therewith, deviation from flatness can occur during the cooling, which is caused by thermal stresses. These thermal stresses can be influenced by the operation of the cooling section. The aim is always to manufacture a flat sheet metal, which exhibits the desired mechanical properties.
Heavy plate as a rule has a thickness of 3 mm or more and thus fulfils the definition in accordance with EN 10029.
A method for cooling heavy plate is known from European patent application EP 2070608 A1. Here the coolant dispensing of the control elements above and below the sheet metal is set individually, especially such that the same coefficient of thermal transfer is present for the upper face of the sheet metal and the lower face of the sheet metal. The disadvantage of this is that despite the comparatively exact determination of the heat transfer coefficients, deviation from flatness in the cooling section can still occur. Also deviations from flatness of the sheet metal which have already occurred before the cooling section could not be rectified with this method.